TorX Architecture for Test Derivation and Execution

University of Twente
Eindhoven University of Technology
Philips Research Laboratories
(THE NETHERLANDS)

Functionality:

Automatic test generation and execution

Tools used:

OPEN/CAESAR

Period:

1999

Description:

Conformance testing is important for developing reactive systems,
since it offers increased confidence in the correctness of the system
by means of experimenting with the system implementation. Using formal
methods allows to define a precise notion of correctness and to automate
the conformance testing process. The Côte-de-Resyste
project (a Dutch joint venture of the Universities of Eindhoven and
Twente and the industrial partners Philips Research and KPN Research)
aims, among other goals, at comparing existing automated test methods
and developing open testing tools together with the underlying formal
theory.

The TorX environment, developed within the Côte-de-Resyste
project, is a tool architecture allowing on-the-fly testing, batch
test derivation and batch test execution for different specification
formalisms. The main characteristics of TorX are flexibility and
openness. Flexibility is obtained by requiring a modular architecture
with well-defined interfaces between the components, allowing to
replace a component by an improved version or by a component
implementing another specification language or implementation relation.
Openness is achieved by choosing, when possible, existing (industry
standard) interfaces to link the components, thus enabling the
integration in TorX of "third party" components that implement
these interfaces.

TorX consists of several components (modules): Explorer,
Primer, Driver, Adapter, and TTCN storage.
The Explorer is an essential component, dependent of the specification
language, which offers functions to explore the transition-graph
of a specification. The interface used between the Explorer and
Primer modules is that provided by OPEN/CAESAR, which offers all the
functionalities needed. This allows to obtain an Explorer for LOTOS
simply by plugging the CAESAR compiler in the TorX architecture.
The TorX environment currently allows automatic test derivation and
execution for the LOTOS, PROMELA, and SDL languages. The use of TorX
is illustrated by testing a conference protocol described in these
specification languages.

Conclusions:

The experiments performed with the TorX architecture showed the
feasibility of automatic test generation and execution for multiple
input languages and/or implementation relations. Both on-the-fly and
batch testing are supported. Further work concerns experimenting TorX
on other case-studies and considering a larger number of test purposes
per case-study. Also, more advanced batch test derivation techniques
are needed in order to reduce human intervention for test deriving.

[Tretmans-Belinfante-99]
Jan Tretmans and Axel Belinfante.
"Automatic testing with formal methods".
In Proceedings of the 7th European International Conference on
Software Testing, Analysis and Review EuroSTAR'99 (Barcelona, Spain),
November 1999.